The acquired immunodeficiency syndrome (AIDS) has become a critical health problem in the United States. Infection with the disease-causing lentivirus-HIV-results in a progressive and debilitating immunosuppression. Because of the period between initial infection with HIV and onset of AIDS is quite variable among individuals, it is important to determine the role of co-factors, such as alcohol abuse, in the development of the disease. It has been reported that ethanol consumption has a detrimental effect on the ability of the host to generate humoral and cellular immune responses. Chronic alcohol abuse is common among drug users, a group at high risk for AIDS, and ethanol associated immunosuppression may act synergistically with HIV-induced immunosuppression to shorten the onset of disease and/or increase the severity of disease. We will use the retroviral-induce murine acquired immunodeficiency syndrome (MAIDS) model to determine the effect of acute and chronic ethanol consumption on the development of HIV-associated immunosuppression. Experiments are designed to determine the effect of ethanol on the replication of the MAIDS virus mixture in infected animals. We will also examine the effect of ethanol on the percentage of T and B cells which are activated by virus infection as well as the subsets of T and B cells responsible for the lymphoproliferation. Finally we will examine the mechanisms of retroviral-induce immunosuppression and the effect of ethanol consumption on generation of these mechanisms.